Intravascular catheters are used in a wide variety of relatively non-invasive medical procedures. Such intravascular catheters may be used for diagnostic or therapeutic purposes. Generally, an intravascular catheter allows a physician to remotely perform a medical procedure by inserting the catheter into the vascular system of the patient at a location that is easily accessible and thereafter navigating the catheter to the desired target site. Vascular passageways distal of the insertion point, such as the neurovascular system, are often narrow and quite tortuous. Furthermore, in order to navigate through the patient's tortuous vascular system, intravascular catheters must be very flexible. If a catheter is sufficiently flexible to reach and pass through the tortuous vasculature, the catheter may lack sufficient column strength or stability to remain in position while, for example, subsequent treatment devices are advanced through the catheter.
It is desirable for an intravascular catheter having sufficient flexibility to reach tortuous vasculature be able to retain a sufficient amount of rigidity while positioned at the target site in order to provide stability and back-out support during a subsequent medical procedure.